超磁致伸缩作动器磁路优化设计

为改善磁路环境,提高超磁致伸缩材料(GMM)的工作性能,在分析超磁致伸缩作动器(GMA)工作原理及GMM特性的基础上提出以减小磁漏、增大磁场强度和提高磁场强度均匀性为设计原则,将GMM棒中轴线上的磁场强度作为评价标准.基于ansoft maxwell对磁路进行电磁学有限元分析,得出磁路中的关键部件导磁端盖和导磁片的结构参数对磁场强度大小和均匀性的影响规律,结合高斯磁通理论分析产生这种现象的原因,在此基础上对结构参数进行设计优化.实验结果显示结构参数优化后GMM棒中轴线上的最大磁场强由55.4 k A/m增大到70.35 k A/m,增幅为26.98%,磁场均匀率由44.22%增大到99.5%.研究表明:导磁端盖主要用来减小磁漏、提高磁场强度且过大或过小的直径和厚度都将会导致漏磁增多,U型导磁片主要用来改善磁路环境、提高磁场强度的均匀性.

Optimization and design for magnetic circuit in giant magnetostrictive actuator

In order to improve and strengthen the performance of giant magnetostrictive materials (GMM), the basic principles of optimization and design are provided that is small magnetic leakage, high magnetic intensity and superior uniformity on the centerline of the GMM rod before analyzing working principle of giant magnetostrictive actuator (GMA) and characteristics of GMM. The laws existed between structural parameters of the key magnetizer and magnetic circuit have been achieved based on Ansoft Maxwell electromagnetic finite element analysis. The cause of these laws has also been revealed by Gaussian flux theory. Then the key structural parameters are all designed and optimized and applied into the GMA. The experiment result indicates that magnetic intensity on the centerline of the GMM rod is raised from 55.4 kA/m to 70.35 kA/m and growth is 26.98%, the uniformity near the GMM rod is increased from 44.22% to 99.5%. The study shows that the permeability cover is mainly to reduce magnetic leakage, improve the intensity of magnetic field and too big or small diameter and thickness will lead to more leakage, U magnetizer is mainly to perfect the magnetic field and improve the uniformity.